Meaning of P0235 Diagnostic Trouble Code (DTC)
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The technical definition of P0235 OBD2 code is: Turbocharger Boost Sensor A Circuit Malfunction
The bad news is this trouble code does not refer to a specific part of the turbocharger or related circuits. It’s a pretty difficult code to fix on your own and if you’re not a qualified mechanic or have a good knowledge or turbochargers, we suggest you take it to your local shop or dealership!
With that being said, the P0235 DTC can be caused by a ton of factors, particularly those that have something to do with boost pressure. This code is common in both import and domestic vehicles equipped with gasoline or diesel motor.
sTeVeXNYCPerformance posted a great guide on youtube showing how to test a turbo boost sensor. His code showing was P0452/P0453, but I thought this video would be helpful to share with you! 🙂
What are the causes of a P0235 fault?
The possible causes of P0235 code are aplenty. Here’s a few things to check first:
- Turbo boost pressure sensor
- Clogged or dirty air filter
- Stuck turbo wastegate (if boost pressure is too high)
- Failing turbo
- Vacuum leak (Learn how to find and fix a vacuum leak)
- Cracked hoses
The most basic thing to check is the turbo boost pressure sensor A. If the sensor is clogged, dirty, or contaminated, it is enough to trigger this generic trouble code. It can also mean the turbo boost sensor is slow to react. If this is the case, replacing the boost sensor will usually correct the issue and clear the check engine light.
But if the sensor is operating within the predetermined values, this generic DTC can be blamed on a vacuum leak in the intake manifold. In some cases, the trouble code can be initiated by a clogged air filter or stuck wastegate valve.
It’s also associated with turbo issues, problems in the exhaust manifold, bad intercooler, turbocharger bearing failure, shorted sensor wiring, and oil leaks in the turbocharger. And since the symptoms will vary, it is always best to consult a competent mechanic to trace the source of the problem.
What are the symptoms of the P0235 DTC?
The symptoms of P0235 code will vary depending on the source of the fault but the most noticeable symptoms are:
- Hissing noises at the wastegate valve
- Excess smoke emanating from the exhaust (most especially at higher engine speeds)
- Rattling noises in the turbocharger housing,
- Poor acceleration
- Sluggish performance
- Fouled-up spark plugs
In most cases, the check engine light and P0235 code are accompanied by serious engine and performance issues, so pay attention. Have the problem checked immediately to reduce the chances of further damaging the motor.
How much does it cost to fix P0235 OBD2 Trouble Code?
The cost of fixing P0235 will depend on the severity of the issue and if you can do the work yourself.
If the problem is a sticky or failing wastegate, the cost will range from $100 to $250 depending on the type of vehicle. Expect to pay more if the issue is caused by a bad turbocharger or intercooler. Buying new performance parts won’t be cheap and can easily cost upwards of $1,500.
But in some cases, the fault can be triggered by a sensor problem or wiring issue, which won’t cost much to fix. A couple hours of shop labor should be all that’s needed which is about $120-$200.
And even though the problem can be remedied by replacing a sensor or fixing the wiring, the bulk of the cost should be spent on checking and rechecking all related components to ensure a reliable and cost-effective repair.